Controlled release and absorption of cetylpyridinium chloride using polymer hydrogels

Interest in the biocide cetylpyridinium chloride (CPC) has resurged based on new studies showing its effectiveness against a wide variety of pathogens. Hydroxyethyl methacrylate (HEMA)-based hydrogels have been developed for the controlled release of CPC. Initial burst release of the biocide can be controlled and sustained release can be achieved for more than two weeks. The burst and sustained release can be adjusted by varying the amount of anionic monomer (AMPSA), crosslink content (DEGDMA), release media, hydrogel surface area, and CPC loading. After removing the CPC-loaded hydrogel from solution and drying, the release of CPC can also be reactivated. Very interesting swelling behavior was observed for CPC-loaded hydrogels due to the electrostatic and hydrophobic interactions between the polymer hydrogel and CPC. In addition, HEMA-based hydrogels can be used to recover or absorb CPC from aqueous solutions. By increasing the amount of AMPSA in the HEMA-based hydrogel, more CPC can be absorbed from solution. The absorption is also enhanced by agitating the solution. (c) 2005 Wiley Periodicals, Inc.